Determination of Non-Flow Shrinkage Ratio in Oriented Fibers

Abstract

A method for the determination of the non-flow shrinkage ratio of oriented fibers is described. The dimensional changes accompanying the transition of an oriented semi-crystalline molecular structure into a disoriented amorphous random coil structure are shown for various types of fibers. Irradiation and fatiguing had a pronounced effect on fiber shrinkage, both in the magnitude of shrinkage and in the temperature range where the shrinking process terminates. A previously derived theory of shrinkage was applied to obtain values for the average crystallite sizes in the fibers studied. These were found to be in accord with estimates made by others using x-ray methods.